Surgery for obesity accomplishes weight loss through restriction of food intake by a restrictive procedure, malabsorption of food by a malabsorptive procedure, or a combination of both restrictive and malabsorptive procedures.
The history of gastric bypass surgery for the treatment of morbid obesity is summarized in The Story of Surgery for Obesity, compiled by Alex MacGregor, MD. Many arrangements of gastric bypass have been tried in prior art. Based on success rate and a low complication rate, two procedures have risen to dominance in the field: vertical banded gastroplasty and Roux-en-y gastric bypass.
Vertical banded gastroplasty was developed by Dr. Edward E. Mason, Professor of Surgery at the University of Iowa in 1982. This technique, and its many variations, involve constricting a portion of the stomach to create a pouch exiting through a stoma using a band of synthetic material that will not stretch under the load of stomach expansion from overeating. In the Mason technique (see FIG. 1A), a portion of the stomach is stapled and a “window” created through which the band is inserted to create the stoma. A variation of this technique developed in Europe involves creation of a pouch and stoma by simply surrounding the fundus of the stomach with a band of material (see FIG. 1B). In both types of procedure, the size of the stoma is critical to the success of the procedure; too much constriction prevents food from passing, too little allows food to pass freely, defeating the purpose of the procedure. To address this condition Dr Kuzmak (Kuzmak, Yap et al. 1990) developed a band incorporating an inflatable balloon coupled to a subcutaneous access port, thereby allowing post operative adjustment of the band through injection and removal of fluid from the balloon bladder (see FIG. 1C).
Vertical banded gastroplasty is a purely restrictive procedure. Limitations and problems of vertical banded gastroplasty include the need for irreversible stomach stapling in the case of the Mason procedure and a tendency for the band to slip out of position in the European and Kuzmak procedures. All versions of vertical banded gastroplasty can be defeated if the patient consumes large quantities of sweets or highly caloric liquids (e.g. milk shakes) which pass easily through the stoma and proceed normally through the full digestive tract. This defeat mechanism has been cited as reason for a lower success rate, as measured by weight loss, for vertical banded gastroplasty in comparison to Roux-en-y gastric bypass.
Roux-en-y gastric bypass (see FIG. 1D) involves isolating (usually by stapling) a pouch in the upper stomach and forming a stoma connecting directly to the jejunum (small intestine). The isolated lower stomach and duodenum are then connected further down the jejunum, thereby keeping the biliopancreatic process intact but further down the digestive tract, thereby reducing absorption of fats. Natural peristalsis of the intestine keeps bile from migrating backwards in the digestive tract. A side effect of introducing bile further downstream of primary digestion is a condition known as Dumping. Dumping occurs when the patient eats refined sugar following gastric bypass, this causes symptoms of rapid heartbeat, nausea, tremor and fainting, sometimes followed by diarrhea. In cases where the patient needs reinforcement to discourage poor eating habits, this unpleasant side effect is a deterrent to sweets and is credited in contributing to the higher success rate of the procedure in comparison to vertical banded gastroplasty.
Roux-en-y gastric bypass is a combination restrictive/malabsorptive procedure. Limitations and problems of Roux-en-y gastric bypass include the extremely invasive, irreversible nature of reconfiguring the digestive system. Also, the anastomotic connections of the procedure are prone to stomal stenosis and obstruction.
Prior inventions of devices for the treatment of obesity have failed to provide, in combination, the three elements of Roux-en-y gastric bypass that made the procedure so successful: restriction of food intake by drastically reduced stomach volume, malabsorption from isolation of the majority of the stomach and part of the intestines from the digestive process, and the negative reinforcement of dumping syndrome that results when sugars and fat reach the jejunum without prior partial digestion.
It is an object of the present invention to induce weight loss in an obese patient through a perorally placed device that restricts food intake.
It is an object of the present invention to induce weight loss in an obese patient through a perorally placed a gastric bypass effecting device that restricts food intake and bypasses some of the absorptive regions of the GI tract thereby inducing malabsorption.
It is an object of the present invention to provide a gastric bypass effecting device and method for the treatment of morbid obesity that duplicates the functional anatomy of vertical banded gastroplasty without high surgical morbidity.
It is an object of the present invention to provide a gastric bypass effecting device and method for the treatment of morbid obesity that duplicates the functional anatomy of Roux-en-y gastric bypass without high surgical morbidity.
It is a further object of the present invention to provide a gastric bypass effecting device and method of accomplishing results comparable to Roux-en-y gastric bypass without abdominal surgery.
It is yet another object of the present invention to provide a gastric bypass effecting device that is removable, and in so doing reverses the procedure and returns the patient to his/her natural anatomy.
It is also an object of the present invention to provide a gastric bypass effecting device that facilitates attachment to the inner lumen of the stomach to form a reduced-size stomach pouch.
It is another object of the present invention to provide a gastric bypass effecting device creating stomach pouch with a precisely designed exit stoma with predicable, repeatable size and performance characteristics and does not require post-operative adjustment.
It is yet another object of the invention to provide a gastric bypass effecting device that is a food conduit bypassing the absorptive components of the upper digestive tract.
It is further an object of the invention to provide a gastric bypass effecting device that is a food conduit that works with the natural peristalsis of the digestive tract to transport material along the digestive tract.
It is also an object of the present invention to provide a gastric bypass effecting device that eliminates the risk of stomal stenosis and reduces the risk of bowel obstruction.
It is an object of the present invention to provide a gastric bypass effecting device for isolating swallowed food from a portion of the absorptive region of the GI tract while allowing stomach acid to mix with the food, thereby breaking down the food to facilitate passage through the device and the non-isolated portion of the GI tract.
It is a further object of the present invention to provide a gastric bypass effecting device and method for allowing excess stomach acid unrestricted passage from the stomach to the lower GI tract in the presence of an installed prosthetic device.
It is another object of the present invention to provide a gastric bypass effecting device and method for synchronizing the action of the stomach pouch stoma valve with that of the pyloric sphincter to facilitate the natural digestive regulatory timing and coordination.
It is yet another object of the present invention to provide a gastric bypass effecting device and method for converting the natural muscular contractions of the stomach into a pumping action within the lumen of the device to transport food contents through the lumen of the device.
It is a further object of the present invention to provide a gastric bypass effecting device and method for converting the natural muscular contractions of the stomach into a pumping action that sucks stomach acid from the pylorus-end chamber into the lumen of the device.